The Under Armour Women's ColdGear® Base 2.0 Leggings are lightweight, flexible & breathable for high activity performance in cool conditions. These leggings are constructed using a special negative grid pattern with each individual cell designed to trap heat without adding bulk. Think of them as long underwear, reengineered for athletes performing at their peak. These leggings feature a soft, brushed grid interior that traps air against your skin, closely managing your body's microclimate to keep you warm & comfortable. The Under Armour Base 2.0 is built for cold weather and higher activity levels.